The present invention relates to an open-end rotor spinning method, device and navel, and more particularly to an open-end rotor spinning method, device and navel for imparting false twist when drawing yarn from the fiber collection groove of the rotor of an open-end rotor spinning device.
In open-end rotor spinning the yarn is formed by the progressing end of yarn picking up fibers from the fiber collection groove of the rotating rotor, with false twist being imparted to the yarn being formed as it progresses from the rotor groove and slides over the surface of a stationary navel during draw-off through a central passageway in the navel. It is desirable that false twist be increased to strengthen the yarn during formation so that a yarn can be produced of strength and quality resembling as much as possible the desirable qualities of ring-spun yarn.
However, in increasing the false twist during open-end rotor spinning there is a problem of unevenness in quality and appearance resulting from the undesirable attachment of wrapper fibers on the yarn as the yarn progresses through the zone of the rotor groove where the loose fibers are being blown into the groove. These wrapper fibers accumulate on the surface of the yarn without being structurally incorporated in the twisted fibers and provide an uneven appearance. This undesirable formation of wrapper fibers on the yarn is increased when more false twist is being imparted to the yarn as it passes through the fiber receiving zone of the rotor.